Die for forming double-twist gimlets



UNITED STATES PATENT OFFICE.

AMOS H. DEUSE AND JAMES s. IDEUSE, or CHESTER, CONNECTICUT.

DIE FOR.FORM N G DOUBLE-TWIST GIMLETS.

SPECIFICATION forming partof Letters Patent No. 224,156, dated February 3, 1 880.

- Application filed June 20, 18:19.

To all whom it may concern;

Be it known that we, AMOS H. DEUSE and. JAMES S. DEUsE, of Chester, in thecounty of Middlesex and State of Connecticut, have invented a new and Improved Die for Making DoubleTwist Gimlets, Bits, 856., of which the following is a specification.

, Figure l is a plan of one half of the die. Fig. 2 is a plan of the other half of the die. Fig. 3 is an elevation of a gimlet or hit made in the same die from a round rod. Fig. 4 is a diagonal sectionon line as m, Fig. 1. Fig. 5 is a diagonal section on line 3 Fig. l.

. Similar letters of reference indicate correspondin g parts. 7

This invention relates to that class of dies that are used for forming the double spiral grooves or twists in. gimlets, bits, and the like.

The invention consists in the peculiar construction of the die, as hereinafter described.

Referring to the drawings, A A represent the halves of the die, having the longitudinal slightly-taperin g groovesb, diagonally across which are the bars a d, which preferabl'y'are east as part of the block. These two parts of the die are to be set together face to face, as shown in section in Figs. 4 and 5, so that the bars in the one half shall lie across those in the other half, and be firmly held in that position while the heated and malleable gimlet or hit blank, which is a round rod, is entered and turned ortwisted into the die until the point is carried beyond the two rear bars, 11, when the die isopened and the blank withdrawn in the condition shown in Fig. 3.

It will be seen that the bars 0, whichare nearest to the front of the die, taper on their faces from their inner to their front ends. The advantage of thus shaping the bars is, that they make the grooves where they run up on the shank, as at e, shallow, thereby leaving the tool stronger at that point than at any other part of the twist.

The rear bars, 01, are made larger than the others, so that they may spread the grooves and swell the tool towardits screw end, making it larger there, so that it may easily bore old-style tool, gives to our tools a great advantage over others, as a deep hole can be bored with them without any binding on the shank or parts above the swell f.

The tool-blank is entered into the dies at a bright-red orhigher temperature, so that it may become easily shaped. c

Having thus described our invention, we claim as new and desire to secure by Letters Patent- 7 v The die for forming double spiral grooves in bits or gimlets, consisting of the two halves A A, having the longitudinal and slightly-tae pering grooves b and the diagonal cross-bars c d, the bars 0 being smaller than bars (1, and tapering on their faces from the inner to the front ends, substantially as shown and described.

AMOS H. pause.

JAMES S. DEUSE.

Witnesses: HIRAM WILLMOT,

CHARLES W. PARKER.

deep. This shape, which is the reverse of the 

